Arithmetic/Geometry » Computer memory
| Symbol | Name | Number of bytes | ||
| KB | kilobyte | 10001 = | 103 | = 1000 |
| MB | megabyte | 10002 = | 106 | = 1 000 000 |
| GB | gigabyte | 10003 = | 109 | = 1 000 000 000 |
| TB | terabyte | 10004 = | 1012 | = 1 000 000 000 000 |
| PB | petabyte | 10005 = | 1015 | = 1 000 000 000 000 000 |
| EB | exabyte | 10006 = | 1018 | = 1 000 000 000 000 000 000 |
| ZB | zettabyte | 10007 = | 1021 | = 1 000 000 000 000 000 000 000 |
| YB | yottabyte | 10008 = | 1024 | = 1 000 000 000 000 000 000 000 000 |
| Symbol | Name | Number of bytes | ||
| KiB | kibibyte | 10241 = | 210 | = 1024 |
| MiB | mebibyte | 10242 = | 220 | = 1 048 576 |
| GiB | gibibyte | 10243 = | 230 | = 1 073 741 824 |
| TiB | tebibyte | 10244 = | 240 | = 1 099 511 627 776 |
| PiB | pebibyte | 10245 = | 250 | = 1 125 899 906 842 624 |
| EiB | exbibyte | 10246 = | 260 | = 1 152 921 504 606 846 976 |
| ZiB | zebibyte | 10247 = | 270 | = 1 180 591 620 717 411 303 424 |
| YiB | yobibyte | 10248 = | 280 | = 1 208 925 819 614 629 174 706 176 |
With 1 byte = 8 bits.
In numbers and units: 1 B = 8 b
Note: The K for kilo would normally be written in lower case (official SI-prefix), however with computer memory it is mostly written in upper case.
Example 1
The smallest piece of information (a letter, number or punctuation mark) that can be stored in a computer is called a byte. A certain book has 400 pages and an average of 3000 characters (letter, number or punctuation mark) per page.
How many MB of storage capacity is needed for this book?
Answer:
400 × 3000 bytes = 1 200 000 bytes = 1.2 × 106 bytes = 1.2 MB
Example 2
A large supercomputer has a memory of 1.6 PB.
How many mobile phones with a memory of 2 GB have the same storage capacity?
Answer:
number of mobile phones = memory supercomputermemory mobile phone
1.6 × 10152 × 109 = 0.8 × 106 = 800 000
Example 3
The speed of a certain internet connection is 15 Mb/s (megabit per second).
What is the speed in MiB/s?
Answer:
15 Mb/s = 15 × 1000 × 1000 : 8 = 1 875 000 B/s
1 875 000 B/s = 1 875 000 : 1024 : 1024 ≈ 1.788 MiB/s